import numpy as np
import pandas as pd

a = pd.DataFrame({'one': pd.Series([1,2,3], index=['a', 'b', 'c']), 'two': pd.Series([4,5,6,7], index=['a', 'b', 'c',' d'])})

print(a)

print(a.sum())
print(a.sum(axis=1))
print(a.mean())
print(a.mean(axis=1))

print(a.sort_values(by='one'))
print(a.sort_values(by='one', ascending=False))
print(a.sort_values(by='a', ascending=False, axis=1))
